From 5fc2dcd64a13502e547201e4b1f5283459a4ba06 Mon Sep 17 00:00:00 2001
From: "marpan@google.com"
 <marpan@google.com@4adac7df-926f-26a2-2b94-8c16560cd09d>
Date: Mon, 1 Aug 2011 21:47:46 +0000
Subject: [PATCH] Change to make the VP8-RTP Fragmentation (FI bits) setting
 (in the payload header) agree with "draft-westin-payload-vp8-02" document.

This issue was raised in: http://code.google.com/p/webrtc/issues/detail?id=31
Review URL: http://webrtc-codereview.appspot.com/92005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@285 4adac7df-926f-26a2-2b94-8c16560cd09d
---
 src/modules/rtp_rtcp/source/rtp_format_vp8.cc | 21 ++++++++++++++++---
 src/modules/rtp_rtcp/source/rtp_format_vp8.h  |  2 ++
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/src/modules/rtp_rtcp/source/rtp_format_vp8.cc b/src/modules/rtp_rtcp/source/rtp_format_vp8.cc
index 358dd8f595..a67e1dfc3b 100644
--- a/src/modules/rtp_rtcp/source/rtp_format_vp8.cc
+++ b/src/modules/rtp_rtcp/source/rtp_format_vp8.cc
@@ -180,9 +180,8 @@ int RtpFormatVp8::WriteHeaderAndPayload(int payload_bytes,
 
     buffer[0] = 0;
     if (hdr_info_.nonReference) buffer[0] |= (0x01 << 3); // N
-    if (!first_fragment_)       buffer[0] |= (0x01 << 2); // FI
-    if (!end_of_fragment)       buffer[0] |= (0x01 << 1); // FI
-    if (beginning_)             buffer[0] |= 0x01; // B
+    buffer[0] |= (GetFIFlag(end_of_fragment) << 1); // FI
+    if (beginning_) buffer[0] |= 0x01; // B
 
     int pic_id_len = WritePictureID(&buffer[vp8_header_bytes_],
         buffer_length - vp8_header_bytes_);
@@ -252,4 +251,20 @@ int RtpFormatVp8::PictureIdLength() const
     }
 }
 
+int RtpFormatVp8::GetFIFlag(bool end_of_fragment) const
+{
+    if (first_fragment_ && end_of_fragment) {
+        return 0x0;
+    }
+    else if (first_fragment_ && !end_of_fragment) {
+        return 0x1;
+    }
+    else if (!first_fragment_ && !end_of_fragment) {
+        return 0x2;
+    }
+    else if (!first_fragment_ && end_of_fragment) {
+        return 0x3;
+    }
+}
+
 } // namespace webrtc
diff --git a/src/modules/rtp_rtcp/source/rtp_format_vp8.h b/src/modules/rtp_rtcp/source/rtp_format_vp8.h
index edb34be8f0..7ee94db850 100644
--- a/src/modules/rtp_rtcp/source/rtp_format_vp8.h
+++ b/src/modules/rtp_rtcp/source/rtp_format_vp8.h
@@ -105,6 +105,8 @@ private:
     // header. Can be 0, 1, or 2.
     int PictureIdLength() const;
 
+    int GetFIFlag(bool end_of_fragment) const;
+
     const WebRtc_UWord8* payload_data_;
     const int payload_size_;
     RTPFragmentationHeader part_info_;